Specifications

Cinterion
®
EHS8 Hardware Interface Overview
2.3 GPS Interface
24
 EHS8_HIO_v04.000 2019-03-04
Confidential / Preliminary
Page 22 of 42
2.3 GPS Interface
2.3.1 GPS Receiver
EHS8 integrates a GPS receiver that offers the full performance of GPS technology. The GPS
receiver is able to continuously track all satellites in view, thus providing accurate satellite po-
sition data.
The integrated GPS receiver supports the NMEA protocol via ASC0 interface. NMEA is a com-
bined electrical and data specification for communication between various (marine) electronic
devices including GPS receivers. It has been defined and controlled by the US based National
Marine Electronics Association. For more information on the NMEA Standard please refer to
http://www.nmea.org.
Depending on the receiver’s knowledge of last position, current time and ephemeris data, the
receiver’s startup time (i.e., TTFF = Time-To-First-Fix) may vary: If the receiver has no knowl-
edge of its last position or time, a startup takes considerably longer than if the receiver has still
knowledge of its last position, time and almanac or has still access to valid ephimeris data and
the precise time.
2.3.2 GPS Antenna
In addition to the RF antenna interface EHS8 also has a GPS antenna interface. The GPS in-
stallation is the same as for the RF antenna interface, except for pad 224 instead of pad 59.
It is possible to connect active or passive GPSS antennas. For active antennas the power is
supplied by ANT_GPS_PWR; see sample application given in Figure 6. In either case the an-
tennas must have 50 impedance. The simultaneous operation of GSM and GPS has been
implemented.